Duplex connector

ABSTRACT

A duplex electrical connector having a housing and an insert in the housing that provides two inbound end apertures that conduct two armored cables to and through a single outbound end aperture. The duplex electrical connector incorporates snap in spring steel retainers to provide a connector that allows rapid and simplified installation of a pair of armored cables into a single junction box outlet. The outbound end of the duplex connector preferably has a smooth outer cylindrical section and includes an outer diameter with flanges that accommodates a spring steel snap in adapter for retention of the duplex connector in a junction box. The two inbound apertures each include a spring steel retainer having outwardly extending tangs that hold it in the inbound aperture and inwardly extending tangs that retain an inserted cable and resist retraction thereof from the duplex connector. The inwardly extending tangs are oriented to guide an inserted armored cable toward the single outbound end of the duplex connector.

FIELD OF THE INVENTION

The present invention relates to cable terminations and moreparticularly to duplex or two-wire cable terminations that snap intoplace and include snap-on cable retainers, neither of which requirestwisting for locking.

BACKGROUND OF THE INVENTION

U.S. patent application Ser. No. 09/007,532 filed Jan. 15, 1998 in thename of Thomas J. Gretz for, “Snap in Cable Connector” describes alocking cable connector composed of three mating pieces that snaptogether and provide a connector for helically wound armored or metalclad electrical conductors. A spring steel adapter is used inconjunction with an electrical junction box to fix the location of thelocking cable connector with respect to the junction box. The firstpiece of the snap in locking cable connector is a die cast memberincluding at its inbound end a smooth outer cylindrical section havingan outer diameter with flanges that accommodates a spring steel adapter.The second piece is a spring steel locking ring provided to receive ahelically wound shielded cable that is inserted into the out end of thedie cast member. The locking ring has outwardly directed tangs thatallow insertion into the die cast member but restrict withdrawal thereoffrom the die cast member. The locking ring also has oppositely oroutwardly directed tangs to receive the armored cable and to restrictits movement in the opposite or withdrawal direction.

The spring steel locking ring has a cut out section that permits slightcompression so that the locking ring may be easily inserted into the diecast member. Once inserted, the locking ring is able to expand to thefull inner diameter of the die cast member to provide a tight and securefit.

SUMMARY OF THE INVENTION

The present invention provides a duplex connector comprising a housingand an insert in the housing that provides two inbound end aperturesthat conduct two armored cables to and through a single outbound endaperture. The inbound end apertures incorporate the snap in spring steelretainers of U.S. patent application Ser. No. 09/007,532 to provide aconnector that allows rapid and simplified installation of a pair ofarmored cables into a single junction box outlet. The outbound end ofthe duplex connector of the present invention preferably has a smoothouter cylindrical section and includes an outer diameter with flangesthat accommodates a spring steel snap-in adapter for retention of theduplex connector in a junction box. The two inbound apertures eachinclude a spring steel retainer having outwardly extending tangs thathold it in the inbound aperture and inwardly extending tangs that retainan inserted cable and resist retraction thereof from the duplexconnector. According to a preferred embodiment of the present invention,the inwardly extending tangs are oriented to guide an inserted armoredcable toward the single outbound end of the duplex connector.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a blown apart view of the duplex connector of the presentinvention.

FIG. 2 is a top view of the duplex connector of the present invention.

FIG. 3 is a plan view of a die-cut blank that is formed into thepreferred spring steel retainer of the present invention.

FIG. 4 is an end view of the preferred spring steel retainer of thepresent invention.

FIG. 5 is a top view of the spring steel retainer of FIG. 4.

FIG. 6 is a side view of the spring steel retainer of FIG. 4.

FIG. 7 is a cross-sectional view of the spring steel retainer of FIG. 4along the line 7—7 of FIG. 4.

FIG. 8 is an end view of the spring steel retainer of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

As shown in the drawings and particularly FIGS. 1 and 2, the duplexconnector 10 of the present invention comprises: a housing 12 having agenerally oval or race track-shaped inbound end 14 and a cylindricaloutbound end 16; an inbound end insert 18; spring steel cable retainers20 and 22 that insert into inbound insert apertures 24 and 26; springsteel locking ring 28 about the outer diameter 17 cylindrical outboundend 16 and retained by flanges 19 and 21; and locking screw 30.According to a preferred embodiment, of the present invention a bushing32 is inserted into outbound end 16. A further preferred embodiment ofthe present invention includes a pair of peepholes 34 that permitviewing of the interior of housing 12 to determine the presence and/orlocation of cable inserted into housing 12 through insert apertures 24and 26.

Housing 12, in addition to previously described generally oval inboundend 14, peepholes 34, and cylindrical out bound end 16 incorporatingouter diameter 17 and flanges 19 and 21 includes shoulder portions 36whose interior surfaces 38 are smooth to guide cables inserted throughinbound end 14 via insert apertures 24 and 26 toward and throughinternal volume 40 of cylindrical outbound end 16. Additionally, housing12 includes, in at least one of its relatively flat top or bottom walls42 and 44, a threaded hole 46 for rotational engagement of screw 30 asdescribed hereinafter. Flange 19 has a slight inward incline to easeinsertion of housing 12 into a junction box aperture and to ease theapplication of spring steel adapter over outer diameter 17. Flange 21 isof a greater diameter than flange 19 to prevent over insertion of springsteel adapter 28.

The various other shapes and features of housing 12 depicted in thedrawings are largely matters of functional design, material minimizationand manufacturability and do not materially affect the functionality ofhousing 12.

Insert 18 comprises a binocular shape and has outer dimensions atinsertion end 46 that are matched to the inner dimensions of generallyoval inbound end 14 of housing 12. End 48 of insert 18 includes a flange50 about both insert apertures 24 and 26 that serves as a stop to limitinsertion of insert 18 into inbound end 14 of housing 12.

Spring steel cable retainers 22 and 24 are inserted into apertures 24and 26 with tangs 52A and 52B engaging openings 54A and 54B in insert18. A complimentary set of tangs 56A and 56B engage matching openingsopposite openings 54A and 54B in insert 18 (not shown).

FIG. 3 is a plan view of the die-cut blank 100 that is formed intospring steel cable retainers 20 and 22. A plurality of lateral slots 102is formed in pairs along blank 100. Adjacent pairs of lateral slots 102are joined by cuts 103 extending between them. U-shaped cutouts 104 arealso formed in blank 100. Blank 100 has a forward edge 124 which ispositioned toward the inside of apertures 24 and 26 when installed ininsert 18 and a trailing edge 126 that faces toward the outside ofapertures 24 and 26 when installed in insert 18. Both the lateral slots102 and U-shaped cutouts 104 are positioned at staggered distances fromforward edge 124. Blank 100 also includes a triangular cut 106positioned near trailing edge 126 and an aperture 108 that is used tohold blank 100 during the manufacturing process when blank 100 is formedinto tubular spring steel retainers 24 and 26. When blank 100 is formedinto its tubular shape, tongue 114 partially enters groove 116 formed onthe opposite end of blank 100. Lateral slots 102 and cuts 103 definestaggered tangs 110A, 110B and 110C that are positioned at varyingprecalculated distances from forward edge 124.

FIG. 4 is an end view of spring steel retainers 20 or 22 from trailingedge 126 after blank 100 has been formed into its tubular shape. A gap118 remains between the two ends of retainer 20 or 22 where tongue 114approaches but does not contact groove 116. The purpose of gap 118 is toimpart a collapsible action to spring steel retainer 20 or 22 so thatslight pressure on the outer periphery thereof will collapse it therebyallowing it to enter apertures 24 and 26 and interact with openings 54Aand 54B in apertures 24 and 26 when inserted therein.

FIG. 4 depicts the orientation of staggered tangs 110A, 110B and 110Coutward projecting tangs 112A and 112B and triangle shaped gripper 122on tubular shaped retainer 20 or 22. Outward projecting tangs 112A and112B are defined by U-shaped cutouts 104 and are positioned essentially180° apart on the outer periphery of spring steel retainer 20 or 22 toprovide stability when inserted into insert 18 as shown in FIG. 1. Itshould be noted that tangs 112A and 112B have angled outward surfacesand relatively flat axial surfaces since the force that needs to beexerted on insert 18 is in direct line with the direction of insertionand removal. Tangs 112A and 112B allow insertion of spring steelretainers 20 and 22 into apertures 24 and 26 while restrictingwithdrawal of spring steel retainer 20 or 22 from insert 18. Analternative arrangement (not shown) could include three tangs spacedeven about the periphery of spring steel retainer 20 or 22 or even fourtangs similarly equally spaced, providing an adequate and equal numberof apertures 54 were provided in insert 18.

FIG. 5 is a top view of spring steel retainer 24 or 26. The edge 111 ofstaggered tangs (110C depicted) that will serve to engage an insertedcable (not shown) are oriented toward forward edge 124 that is orientedas described above. By being oriented toward forward edge 124, edges 111of staggered cable tangs (110C depicted) are able to grip and hold anarmored cable (not shown) that is subsequently inserted from thedirection of trailing edge 126. Conversely, outward projecting tangs(112B depicted) will be oriented with edges 113 toward trailing edge 126thereby resisting removal of spring steel retainer 20 or 22 fromaperture 54 and consequently insert 18. An alternative embodiment mightinclude the use of only a pair of tangs, 110A and 110C oriented 180° onefrom another with the elimination entirely of tang 110B. While not asdesirable from several standpoints, namely less restraining forceagainst removal of an inserted cable, and less directional force guidingan inserted cable toward the center of housing 12 as described below,such an arrangement would provide an adequate structure and is clearlycontemplated as within the scope of the appended claims.

The surfaces of tangs 110A and 110C have a relatively flat axial surfacewith tangs 110A and 110C angled inwardly toward the inner end of insert18. Tangs 112A and 112B and 110A, 110B and 110C are lanced from thecylindrical wall of spring steel retainer 20 or 22. The inside ends (111depicted in FIG. 5) are bent in a radial direction and jagged withpoints since the force that needs to be exerted upon insertion of anarmored cable is helical or twisting in nature and a flat surface wouldsimply slide along the groove of such an armored cable thereby lesseningthe restraining force of tangs 110A and 110C. Tang 110B may be flat andnot bent in, so long as tangs 110A and 110C serve to appropriately guidethe armored cable over tang 110B so that it may contribute to therequired retraining force that pushes an inserted cable toward the“untanged” wall of spring steel retainer 20 or 22 thereby providing anarea between tangs 110A, 110B and 110C and the interior wall of springsteel retainer 20 or 22 that is less than the diameter of the insertedcable.

FIG. 6 is a side view of spring steel retainer 20 or 22 of FIG. 4. Ashown in this Figure, outward projecting tangs 112A and 112B are atstaggered distances from trailing edge 126. Two staggered cable tangs110B and 110C are depicted at staggered distances from forward edge 124.

FIG. 7 is a cross-sectional view of spring steel retainer 20 or 22 takenalong line 7—7 of FIG. 4. Staggered cable tang 110C is depictedextending inwardly into tubular shaped spring steel retainer 20 or 22.An angled end 115 is shown near the end of staggered cable tang 110C.

FIG. 8 is an end view of spring steel retainer 20 or 24 as viewed fromforward edge 124 showing staggered cable tangs 110A, 110B and 110Coriented toward forward edge 124.

It is important to the most successful practice of the present inventionthat spring steel retainers 20 and 24 be oriented within apertures 24and 26 such that tangs 110A, 110B and 110C are oriented and depicted inFIG. 1, i.e. that their orientation is such as to server to guide cableinserted therein toward the center of housing 12. Such an orientation ofspring steel cable retainers 20 and 22 simplifies the insertion of apair of cables through hosing 12 by pre-positioning the cables towardthe center of housing 12 as they are inserted thereby making the task ofpushing them through cylindrical volume 40 much easier.

Spring steel adapter 28 includes a slot 29 to permit expansion prior tobeing fitted over diameter 17, and includes a plurality of tangs 31 toprevent removal of adapter 14 from the aperture of a junction box (notshown) after installation into such an aperture. A more detaileddescription of adapter 14 and its operation can be found in U.S. Pat.No. 5,373,106 entitled’ “Quick Connect Fitting for Electrical JunctionBox”, assigned to the same assignee as the present invention andincorporated herein by reference.

Peepholes 34 are provided in housing 12 to permit viewing of cablelocation within housing 12 during and subsequent to cable installation.

According to a highly preferred embodiment of the present invention, abushing 32 comprising a cylindrical body 58 having a flange 60 at itsoutbound end is inserted to prevent accidental damage to inserted cable.Bushing 32 is designed to frictionally engage the interior ofcylindrical outbound end 16 of housing 12 and is preferably made of apolymeric material that serves to cushion cable inserted into housing 12and exiting therefrom through cylindrical outbound end 16.

Assembly of duplex connector 10 is achieved by insertion of spring steelcable retainers 20 and 22 into apertures 24 and 26 of insert 18 suchthat tabs 52A and 52B engage openings 54A and 54B and their opposingcounterparts (not shown) achieve similar engagement. Insert 18 is theninserted into inbound end 14 of housing 12 until fully seated. Screw 30is then tightened into threaded hole 46 and engages surface 56 to retaininsert 18 in housing 12. Spring steel adapter 28 is then applied overflange 19 and around outer diameter 17.

While duplex connector 10 can be fabricated from a variety of materialsincluding metals and polymeric materials, it is preferred that it befabricated as a die cast assembly with housing 12 and insert 18 bothbeing die cast from a suitable metallic alloy. The other elements ofduplex connector 10 will of course be fabricated from the materialsindicated hereinabove.

As the invention has been described, it will be apparent to thoseskilled in the art that the same may be varied in many ways withoutdeparting from the spirit and scope of the invention. Any and all suchmodifications are intended to be included within the scope of theappended claims.

What is claimed is:
 1. A duplex electrical connector comprising: (a) ahousing having a cylindrical outbound end and a generally oval inboundend; and (b) a generally oval insert in said generally oval inbound endand comprising a pair of parallel cylindrical apertures having inboundand outbound sides; each of said apertures including a tubular springsteel retainer adapted to receive an armored cable and lock said armoredcable into said housing, each said tubular spring steel retainer havinga first set of outwardly extending tangs that permits insertion of saidtubular spring steel retainer into said aperture and by engaging saidcylindrical aperture restricting withdrawal of said tubular spring steelretainer from said aperture, and a set of inwardly extending tangs toreceive and engage an armored cable having grooves inserted from saidinbound side and restrict its removal from said tubular spring steelretainer from said inbound side.
 2. The duplex electrical connector ofclaim 1 including a smooth internal transition zone between saidcylindrical outbound end and said generally oval inbound end.
 3. Theduplex electrical connector of claim 2 further including a tubularspring steel adapter having outwardly extending tangs and capable ofengaging an aperture in an electrical junction box with said tangs,about said cylindrical outbound end and flanges on said cylindricaloutbound end to retain said tubular spring steel adapter on saidcylindrical outbound end.
 4. The duplex electrical connector of claim 2wherein said set of outwardly extending tangs comprises a pair of tangsspaced at 180° from one another on said spring steel retainer.
 5. Theduplex electrical connector of claim 2 wherein said set of inwardlyextending tangs comprises a pair of tangs spaced apart 120° and orientedto direct an inserted cable toward the center of said generally ovalshaped inbound end.
 6. The duplex electrical connector of claim 2wherein said set of inwardly extending tangs comprises three tangs, twoof said tangs having triangular tips and a third tang that has a squaretip, that engage said grooves of an inserted armored cable with saidtangs having triangular tips spaced apart on either side of said thirdtang that has a square tip, said three tangs being oriented so as toforce as an inserted cable toward the center of said housing.
 7. Theduplex electrical connector of claim 6 wherein said two tangs havingtriangular tips are spaced about 180° apart on the inside periphery ofsaid tubular spring steel retainers.
 8. The duplex electrical connectorof claim 2 wherein said housing includes a flat portion in saidgenerally oval inbound end and a threaded screw hole in said flatportion for insertion of a screw that contacts said insert therebyretaining said insert in said housing.
 9. The duplex electricalconnector of claim 8 further including a bushing in said cylindricaloutbound end that serves to protect an inserted cable from abrasion. 10.A duplex electrical connector comprising: (a) a housing having acylindrical outbound end, a generally oval inbound end and a smoothinternal transition zone between said cylindrical outbound end and saidgenerally oval inbound end; (b) a generally oval insert in saidgenerally oval inbound end and comprising a pair of parallel cylindricalapertures having inbound and outbound sides; each of said parallelapertures including a tubular spring steel retainer adapted to receivean armored cable and lock said armored cable into said housing, saidtubular spring steel retainers each having a pair of outwardly extendingtangs that permit insertion of said tubular spring steel retainer intosaid aperture by engaging openings in said cylindrical apertures therebyrestricting withdrawal of said tubular steel retainer from saidaperture, and a set of three inwardly extending tangs to receive andengage an armored cable inserted from said inbound side and restrict itsremoval room said tubular spring steel retainer, said inwardly extendingtangs being oriented to direct an inserted cable toward the center ofsaid housing; and (c) a tubular spring steel adapter having outwardlyextending tangs and capable of engaging an aperture in an electricaljunction box with said tangs, about said cylindrical outbound end andflanges on said cylindrical outbound end to retain said tubular springsteel adapter on said cylindrical outbound end.